Nalorphene `(C_(19)H_(21)O_NO_(3))`, similar to morphine, is used to combat withdrawal symptoms in narcotic users. Dose of nalorphene generally given is 1.5 mg. calculate the mass of `1.5-10^(-3)m` aqueous solution required for the above dose.

Answer

3.216g

Explanation

Molecular mass of nalorphene `(C_(19)H_(21)NO_(3))`
`= 12 xx19+1 xx 21 +14+ 16 xx 3 = 311 "g mol"^(-1)`
` 1.5 xx 10^(-3)` m aqueous solution contains nalorphene
`= 1.5 xx 10^(-3) xx 311 "g kg"^(-1) = 0.4665 "g kg"^(-1)`
Weight of solution `=1000g +0.4665 g = 1000.4665 g`
`(1.5 xx 10^(-3) xx 311)` g of nalorphene is present in solution
= 1000.465 g
1.5 mg or `1.5 xx 10^(-3)` g of nalorphene is present in solution
`=(1000.465)/(1.5xx10^(-3)xx311)xx1.5xx10^(-3)=3.216g`